This disclosure relates to an electrostatic sensing device.
Electrostatic sensing devices (surface potential sensing devices) are used to measure the surface potential of a photoconductor drum or the electrostatic charge of an electronic device being manufactured. The electrostatic sensing devices measure the electric field generated by an electrified object as a measurement target and convert the measured value into a surface potential. A typical electrostatic sensing device includes a sensing electrode and an openable/closable chopper to measure the electric current generated by the electric field from a measurement target and flowing in the sensing electrode.
JP 2012-43411 A discloses a thin film charged body sensor for sensing a motion of a charged body (for example, a finger) which is in contact or not in contact with a panel. JP 2012-43411 A further discloses that the thin film charged body sensor includes an active layer including an oxide semiconductor.